State regulators on Wednesday said they levied a $900,000 civil penalty against Texas electricity supplier Spark Energy for failing to adhere to state laws requiring that consumers receive timely and accurate billing information.

In a draft decision, the Public Utilities Regulatory Authority said Spark had been delinquent in supplying timely information about upcoming rates to the state's utilities, which they pass along in billing materials sent to customers who have elected to use a third-party supplier.

The effect was that "numerous customers" didn't know how high their upcoming bills would be, PURA said. Among them was Sen. Len Suzio (R-Meriden), who wrote a letter to PURA in February complaining that his "next cycle rate" in his bill was listed as 7 cents per kilowatt hour, but then turned out to actually be nearly 13 cents.

Suzio has argued that Eversource (which is his utility provider) should also be held accountable, because it "knowingly inserted rate information that it didn't have."

"That's absolutely not true and we've clearly shown that to PURA," Gross said. "The program is designed so that only the third-party suppliers can automatically and securely provide their data. While we have no affiliation with these companies, we continue to work with PURA and the Office of Consumer Counsel to help ensure our customers receive accurate information on their energy bills from them."

PURA's decision noted that Spark has a history of prior non-compliance with state laws, including failing to report its intrastate gross revenue (which earned it a $5,000 fine in 2014) and failing to comply with new billing disclosure rules for more than a year.

In the latter situation, PURA said Spark provided false assurances that it was in compliance. Now, the agency says it will monitor Spark for the next year, and that further violations or non-compliance could lead to additional penalties or revocation of its license.

Spark has 20 days to request a hearing on the $900,000 fine, should it choose to do so, according to PURA.

[This story was updated at 2 p.m. Thursday to provide comment from Eversource.]